Metal shelving is the workhorse of almost every stockroom, workshop and warehouse in the country. It is cheap per metre of storage, quick to put up, and — in its heavier grades — strong enough to carry serious weight. But "metal shelving units" covers everything from a flat-pack five-tier rack to a fully engineered industrial system, and the wrong choice either buckles under load or wastes money on capacity you will never use. This guide explains the main types of steel shelving, the specs that actually decide whether a unit will cope, and a simple method for choosing.
What counts as metal shelving?
Metal (steel) shelving is hand-loaded storage: you place goods on the shelves by hand rather than with a forklift. That is the key line that separates it from pallet racking, which is built to take palletised loads by truck. Within the hand-loaded world, units range from light domestic racks up to heavy-duty industrial systems rated for hundreds of kilos per shelf. Choosing well is mostly about matching the shelf load rating and the bay size to what you actually store.
The main types of metal shelving
Boltless (rivet) shelving. The most common commercial format. Uprights, beams and shelf panels clip together on a rivet-and-lug system with no loose nuts and bolts, so a bay goes up in minutes and shelf heights adjust easily. Ideal for stockrooms, archives, workshops and general storage where loads are moderate and you want flexibility.
Heavy-duty industrial shelving. Engineered steel systems for genuinely heavy loads. Our heavy-duty shelving range is built around the SSI Schaefer R3000 system — a modular, boltless-lug design in galvanised or painted steel that combines shelving, long-span and upright storage in one framework, with drawers, dividers, panels, doors and bins available to tailor the layout. This is the grade to specify when a light rack simply will not do.
Longspan shelving. Wider bays (typically 900–1,800mm between uprights) for bulky or long items that would overhang a standard shelf. It is still hand-loaded, sitting between standard shelving and pallet racking. We cover it in detail in our longspan shelving guide.
Small-parts and tray shelving. For components, fixings and picking, tray-based units like the GPC Small Parts Shelf Units (ASU) let each tray withdraw and suspend from the shelf for around 90% clear picking, with a full range of tray sizes and dividers. Pair these with the wider bays for a tidy stores area.
Vertical and sheet racking. Sheet material, bar stock and long loads store better upright or on cantilever arms than on flat shelves — see the vertical storage racks and sheet racking in the racking & shelving collection.
The specs that matter
Shelf load rating (UDL). The single most important figure. It is quoted as a uniformly distributed load — the weight a shelf carries when it is spread evenly, not concentrated in one spot. Concentrated or point loads reduce the safe figure, so always leave headroom over your heaviest planned shelf.
Bay dimensions. Height, width and depth of each bay. Deeper shelves hold more but make items at the back harder to reach; taller bays store more per square metre but need safe access steps for the top levels.
Shelf material. Steel shelves for heavy or oily loads; chipboard or melamine decks for lighter, cleaner goods. Galvanised finishes resist damp and corrosion better than painted ones in unheated or outdoor-adjacent areas.
Construction and adjustability. Gauge of steel, welded versus clipped joints, and how easily shelves reposition all affect durability and flexibility. A boltless lug system that adjusts on the fly is worth having if your stock profile changes.
Starter and extension bays. Buy a starter bay first, then add extension bays that share an upright with the neighbour — cheaper and tidier than standalone bays when you run a continuous run.
How to choose in five questions
1. What is the heaviest shelf load? Pick a UDL comfortably above it. 2. What size and shape are the goods? Small parts, boxed stock, or long/bulky items each point to a different format. 3. How is it accessed? Frequent picking favours shallower, waist-height shelves; bulk storage can go higher with steps. 4. What is the environment? Damp, unheated or wash-down areas favour galvanised steel. 5. Will it grow? If so, choose a system with extension bays and accessories so you can expand without replacing.
Laying out a stockroom or storeroom with metal shelving units
Choosing the right bay is half the job. The other half is where the bays go, and it is the half most people skip. A stockroom or storeroom is hand-loaded and hand-picked, and that sets three rules that a warehouse aisle fed by fork trucks does not have to obey: shelf heights a person can reach, depths a person can see into, and a layout arranged around the picking flow rather than around the walls.
Work backwards from the picking flow. Fast-moving lines belong nearest the door or the hatch, at what is usually called the golden zone — roughly between waist and shoulder height, where an item can be taken without bending or reaching. Slow movers go high or low. Getting only this right typically saves more time than any other single decision in a stores area.
Depth is the specification people get wrong most often. Shelve as deep as you can genuinely see and reach into: 300–450 mm for small stock, up to 600 mm for cartons. Go deeper than that and stock hides at the back — you lose it, re-order it, and find it eighteen months later. A deeper shelf is not more storage if nobody can see what is on it.
Aisles and bay arrangement. A person carrying a tote needs about 900 mm of clear aisle; a picking trolley needs appreciably more, so measure the trolley you actually use rather than assuming. Run single rows of bays against the walls and back-to-back doubles down the middle of the room. Use the full height available — taller bays plus proper access, not everything spread out at waist height across twice the floor area. Check bay height against ceiling and sprinkler clearances before ordering, not after.
Label locations, not just products. A bay / level / position reference on every location makes picking and stock counting faster immediately, and it is the foundation any stock-control system will need later. It costs an afternoon with a label printer.
Anything stored above safe reach needs steps or a mobile access platform, and it needs to be planned into the order from day one. The alternative — a chair, an upturned crate or a pallet — is how stockroom injuries happen, and it is not defensible under the Work at Height Regulations.
Small parts, trays and totes
Fixings, spares and electrical components live in hundreds of small locations, and they pick far faster from purpose-made units than from boxes on an open shelf. The GPC Small Parts Shelf Units (ASU) use withdrawable trays that suspend from the shelf for roughly 90% clear access, in tray sizes from 90 × 117 × 300 mm up to 140 × 234 × 500 mm, with dividers. One tray per part number beats a shoebox every time.
Where stock is decanted into standard containers, GPC Tote Pans & Racks put welded steel rack frames behind the picking face, with bin retainers holding each tote at an angle you can see into — well suited to kitting benches and back-of-counter stores. Our guide to small parts storage covers the formats in more detail.
Buying to extend: starter bays, extension bays and finish
Two practical points that decide the cost per metre of a stores area. First, buy a starter bay and then extension bays that share an upright with the neighbour — a continuous run built from standalone bays costs more, wastes floor width and looks it. Second, match the finish to the room: galvanised for cold, damp or unheated stores; painted or powder-coated where the room is dry and heated. Retrofitting the wrong finish means replacing the bay.
Loading and using it safely
Under PUWER 1998, work equipment must be suitable, in good order and used correctly. Put the heaviest items on lower shelves to keep the unit stable, spread loads evenly rather than piling them at one end, and never climb the shelving — use proper steps or a platform for high levels. Tall or free-standing runs may need floor fixing or bracing; follow the manufacturer's instructions and carry out your own risk assessment for the loads and location.
Metal shelving FAQ
How much weight can metal shelving hold? It depends entirely on grade. Light racks carry tens of kilos per shelf; heavy-duty industrial systems carry hundreds. Always work to the quoted UDL for that specific unit.
Boltless or bolted shelving — which is better? Boltless is faster to assemble and adjust and suits most commercial storage. Bolted or fully welded construction can offer extra rigidity for the very heaviest static loads.
Is metal shelving the same as pallet racking? No. Shelving is hand-loaded; pallet racking takes palletised loads by forklift. If you are torn between them, our industrial shelving vs pallet racking guide breaks down which suits your stock.
Can I use commercial metal shelving in a garage? Yes — commercial steel shelving is far stronger than most flat-pack garage kits. See our garage shelving & racking guide for choosing units that fit and last in an unheated garage.
How deep should stockroom shelves be? As deep as you can see and reach into — 300–450 mm for small stock, up to 600 mm for cartons. Deeper than that and stock hides at the back of the shelf.
Can I add more bays to a storeroom later? Yes. Boltless systems extend with add-on bays that share a common upright, so buy a starter bay now and extend as the stock profile grows.
Do I need to fix shelving to the wall or floor? Follow the manufacturer's guidance — taller or heavily loaded bays should be fixed back or run back-to-back for stability.
Load figures and specifications refer to the specific products listed and should be confirmed for your application. This guide is general information, not a substitute for the manufacturer's instructions or your own risk assessment.
Browse the full racking & shelving range and the heavy-duty shelving systems, or talk to us about specifying a stores layout.